PURPOSE: To simply manufacture a semifinished material capable of simply making a flower-like rosette from various materials by attaching a drawstring to a band of a flexible material in a specific state and forming at least one longitudinal edge of the band into a non-linear contour.

CONSTITUTION: A drawstring 14 is attached to the vicinity of a straight longitudinal edge 39 of a band 1 of a flexible material such as fiber woven fabric, a synthetic resin sheet or paper so as to expose the drawstring to the top and the bottom sides of the band 1 alternately. Spacings 30 of exposure interval are determined so that the spacings have a length to make a desired fold and pleat size. A second longitudinal edge is formed into a non-linear contour 31 and the width of the band, the size of curve of the non-linear contour 31 and the depth of the arc stand are set according to the desired form of the flower- like rosette to be produced.